Grease guns are used to deliver lubrication in a variety of mechanical settings, including for lubricating bearings. Industrial grease guns generally include a piston that draws in grease from a cartridge into a priming chamber during an upstroke, and expels the grease from the chamber during a downstroke. Grease guns can be powered in a variety of ways, for example, by hand, pneumatics, or by an electric driver.
Electrically-driven grease guns generally rely on a battery to provide the power source. However, sensing capabilities in such grease guns are typically limited. For example, some grease guns may count the number of piston strokes and, with a known grease dose per piston stroke, determine the amount of grease that is expelled over a period of time.
Such determinations may be successfully implemented in a variety of applications. However, in others, they may be inaccurate and/or insufficient. For example, even with such stroke-counting capabilities, the grease-use calculations assume that only grease was fed into the priming chamber. In some cases, however, air pockets may develop, which are fed to the grease gun. Accordingly, the downstroke of the piston may result in expulsion of the air, instead of grease, resulting in the grease-use calculation being incorrect.
Furthermore, grease gun cartridges run out of grease, resulting in a cessation of grease delivery through the grease gun. However, the grease gun piston may continue being driven when the cartridge is empty, which can result in cavitation.